Predictors of Conversion During Minimally Invasive Gastrectomy for Malignancy

Abstract

IntroductionImplementation of minimally invasive gastrectomy (MIG) for malignancy is increasing. However, risk factors for conversion to open surgery during laparoscopic and robotic gastrectomy are poorly understood. This study aimed to determine the risk factors for, and impact of, conversion during oncologic resection. MethodsThe National Cancer Database (NCDB) was used to identify patients with clinical stage I-III gastric cancer from 2010 to 2017. Chi-squared test and t-test were used to compare the robotic versus laparoscopic groups. Propensity score weighted multivariable logistic regression was used to evaluate factors associated with conversion to open surgery. ResultsOf 6990 patients identified, 5702 (81.6%) underwent a laparoscopic resection and 1288 (18.4%) underwent robotic-assisted resection. Conversion rates were 14.7% and 7.8% for laparoscopic and robotic gastrectomy, respectively. The robotic approach was associated with lower likelihood of conversion compared to laparoscopic approach (odds ratio [OR] = 0.470, P < 0.001). Other factors predictive of conversion included tumor size >5 cm compared to <2 cm (OR 1.714, P = 0.010), total gastrectomy compared to partial gastrectomy (OR 2.019, P < 0.001), antrum/pylorus (OR 2.345, P < 0.001), and body (OR 2.152, P < 0.001) tumors compared to cardia tumors. Compared to those treated with laparoscopic and robotic gastrectomy, patients who underwent conversion experienced significantly longer hospital length of stay and higher rates of positive surgical margins. ConclusionsLaparoscopic gastrectomy was associated with a higher conversion rate compared to robotic gastrectomy. Conversion to open surgery was associated with a significantly longer length of stay and higher rates of positive margins. Identification of risk factors for conversion can aid in appropriate modality selection.